The present invention relates to a tool head for use with an automatic cable tie installation system and, more particularly, to an automatic tie tool head including an anti-jam tensioning gear mechanism providing improved performance and reliability.
As is well known to those skilled in the art, cable ties are used to bundle or secure a group of articles such as electrical wires or cables. Cable ties of conventional construction include a cable tie head and an elongate tail extending therefrom. The tail is wrapped around a bundle of articles and thereafter inserted through a passage in the head. The head of the cable tie typically supports a locking element which extends into the head passage and engages the body of the tail to secure the tail to the head.
Although cable ties are often installed manually, it is desirable in certain applications to utilize an automatic cable tie installation system wherein cable ties are dispensed from a remote dispenser, and thereafter delivered to a tool head for application about a bundle of wires positioned within the jaws of the tool head. Automatic cable ties installation systems are well-known in the art, and are disclosed for example in U.S. Pat. Nos. 6,279,620, 4,790,225, 4,498,506 and 3,946,769. It will be appreciated that the disclosed tool heads include a plurality of subassemblies each having multiple moving parts, the subassemblies cooperating together to deliver, tension and cut the cable tie. To be commercially practical, the tool head must be capable of repeatedly applying a cable tie about the bundle of articles inserted within the jaw assembly without jamming. The tool head must also be able to complete a cycle (wherein one cable tie is wrapped, tensioned and cut) within a sufficiently short interval of time.
Those skilled in the art will appreciate that prior art tool heads can experience internal jams with respect to the tensioning/strap ejection portion of the tool head. More particularly, the tail of the installed tie, once severed from the bundled wires (after tensioning of the cable tie), is directed into an exit chute whereby the excess tail portion may exit the tool head. There are times, however, when the severed tail, rather than being directed into the exit chute, is misdirected under the guide ramp defining the leading edge of the exit chute. This then squeezes the severed tail between the guide ramp (which is a fixed portion of the tool head) and the rotating tension gear, thus causing a jam within the tool head.
There is therefore a need in the art for an automatic tie tool head which is capable of repeatedly tensioning a cable tie, severing the excess tail portion from the tensioned tie, and thereafter ejecting the severed tail portion without risk of the severed tail portion becoming jammed in the tool head.